There is much interest in developing alternate fuels for internal combustion engines and the like. There is particular interest in ignition promoters for compression-ignition engines, for example, diesel engines, due to the high cost and uncertain availability of petroleum based fuels and environmental concerns. Among potential fuels that have received considerable attention, especially for diesel engines, are the lower alcohols, such as methanol, ethanol, etc. Methanol is of particular interest since it can easily be obtained from natural gas as well as form the large coal reserves available in many Western countries. Unfortunately, methanol or ethanol alone have poor compression-ignition characteristics making them unsuitable for use in conventional diesel engines. It is known however that ignition promoters can be added to lower alcohols to make them suitable for use in diesel engines.
U.S. Pat. No. 5,096,462, which is hereby incorporated by reference, discloses that effective ignition promoters suitable for incorporation into alcohols produce excellent fuels for use in internal combustion engines. The ignition promoters are obtained by removing cellulose from biomass, using any suitable procedure therefor, reacting the remainder of said biomass with an oxirane and thereafter reacting the resulting reaction product with nitric acid under nitrating conditions.
We have now discovered an exceeding simple process for producing an ignition promoter that can be introduced into an alcohol to obtain a fuel suitable for use in internal combustion engines, in particular compression-ignition engines, that involves combining a sugar with a selected solvent, reacting the resulting solution with an oxirane and thereafter reacting the product obtained with nitric acid under nitrating conditions.